Mouse problem..

hello..
one stupid problem of my mouse.
when i make lj i make the pre strafe my sensitivity is 3 but when i press w+d
and push the mouse righ my sensitity is like 1 and my pre strafe is shit (its like 265-268) ,this happen when i overclock my usb pooling rate to 250hz..
on 125hz there is no problem ..
if someone can help pls reply :)

yea but when i overclock the usb of the mouse my strafes for lj are better then normally ;\